Dialyzable drugs
Background
Factors Influencing Dialyzability
Molecular weight
- Smaller molecular weight substances will pass through the dialysis membrane more easily than larger molecular weights.
Protein Binding
- Drugs with a high degree of protein binding will have a small plasma concentration of unbound drug available for dialysis, making them poorly dialyzable or requiring multiple sessions.
Volume of Distribution
- Drugs with large volumes of distribution usually due to lipid solubility and low plasma protein binding are poorly diliazable.
Plasma clearance
- Although plasma clearance may be beneficial, increasing plasma clearance will dcrease dialysis clearance.
Dialysis Flow Rates
- Greater degrees of dialysis can be achieved with faster dialysate flow rates if the dialysate drug concentrations is low. As the concentration of drug is increased in the diasylate the flow rate needs to be lowered.
Common Dialyzable Drugs
Mnemonics BLISTMED and ISTUMBLED:
- B - Barbiturates
- L - Lithium
- I - Isoniazid
- S - Salicylates
- T - Theophyline/Caffeine (both are methylxanthines)
- M - Methanol, metformin
- E - Ethylene glycol
- D - Depakote, dabigatran
- Others - Carbamezepine
- I - INH/isopropyl alcohol
- S - Salicylates
- T - Theophylline
- U - Uremia
- M - Methanol
- B - Barbiturates
- L - Lithium
- E - Ethylene glycol
- D - Dabigatran, depakote